Vox Weather meteorologist Michelle du Plessis said La Niña events typically bring above-average rainfall and cooler conditions to South Africa.
“La Niña often results in wetter and slightly cooler conditions during the summer rainfall season. As the Pacific Ocean moves towards neutral conditions, extreme rainfall events are less likely, but the atmosphere does not adjust immediately,” she told Farmer’s Weekly.
She added that residual La Niña effects may still influence local weather in April and May. “Farmers could still experience periods of heavy rain or unexpected dry spells. These short-term anomalies are important to monitor because they occur during sensitive crop development stages.”
Risks and recommendations
Maize is currently in the pollination stage in several of South Africa’s production regions, a phase that is critical for determining yield potential.
Du Plessis said temperature and soil moisture are key factors for effective pollination: “Moderate daytime temperatures and sufficient soil moisture are essential for successful pollination and kernel formation. High temperatures combined with dry conditions can reduce pollen viability and limit yields.”
Speaking to Farmer’s Weekly, Grain SA agricultural economist Marguerite Pienaar said farmers are taking practical steps to mitigate risks.
“For those who planted outside optimal windows or had to replant due to early-season heavy rains, focusing on high-yielding hectares and drought-resistant cultivars is a priority. Prevention is better than cure.”
She added that even short periods of stress can have a noticeable impact on pollination and yield: “While brief dry spells are usually manageable, sustained moisture stress during pollination can reduce kernel set and overall yield potential.”
Late-season weather variability
As the season transitions towards winter, cut-off low-pressure systems or early cold spells could still impact late-planted crops and harvesting.
“Occasional autumn cut-off lows can lead to widespread rainfall, disrupting harvest schedules or affecting late-planted crops,” Du Plessis said.
“Higher-altitude areas may experience early frost, so producers should continue to monitor forecasts closely.”
Early forecasts suggest a potential warming of the Pacific Ocean, which could trigger El Niño conditions in the 2026/27 season. However, Du Plessis noted that these projections remain uncertain.
“Seasonal forecasts made this early carry a high degree of uncertainty, particularly during the autumn predictability barrier. Confidence in the outlook typically improves by mid-year, around June or July,” she explained.
Pienaar added that farmers are already considering strategies to reduce potential risks.
“Planting inside optimal windows, selecting drought-resistant cultivars, and understanding per-hectare margins are essential steps. This helps mitigate risks of mid-summer droughts or heat stress during a possible El Niño year.”
In addition, Pienaar said the seasonal outlook could influence farmer profitability. “A larger-than-expected harvest can improve cash flow and help producers recover from previous volatile seasons. However, if supply exceeds demand without support from export markets, prices may fall below export parity, which negatively impacts profit margins.”
She added that international demand will be a decisive factor for profitability. “Global market conditions, including ample world supply, can affect local prices, making strategic management of inputs and planting decisions even more important.”
With the end of La Niña in sight, farmers are advised to monitor short-term forecasts and field conditions carefully. Both Du Plessis and Pienaar said vigilance over the next few weeks, especially during pollination and grain filling, will be critical for safeguarding yield and financial outcomes.
